This invention relates to projectiles particularly for use in shells for shotguns and other smooth bore weapons.
Conventional buckshot and slugs of the type used in shotguns and the like have no means of stabilization and are accordingly erratic in flight and somewhat short ranged. It is accordingly an object of the present invention to provide an improved form of projectile for use in shotguns and the like which is stabilized in flight over a longer range than conventional shot thereby providing a more effective dispersion pattern.
Projectiles in accordance with the invention are substantially teardrop-shaped having a relatively blunt, substantially hemispherical nose portion, and an elongate tail portion tapering smoothly from a junction with the nose portion to a relatively sharp tip. Preferably, the projectile is provided with grooves in an outer surface of the nose portion radiating from a central location on the nose portion in curved manner substantially to the junction with the tail portion for imparting a stabilizing, in-flight spin to the projectile about an axis connecting the central location and the tip.
Projectiles in accordance with the invention may be used either singly in a shell case as a slug or in multiple configuration as buckshot. In the latter case, the projectiles are preferably stacked on end in one or more columns in the shell case and for this purpose, preferably the projectile has a recess in the nose which receives the tip at a tail end of the preceding projectile.
In use, the grooves, in the form of turbo grooves spin the projectile in flight and being on the projectile's nose portion, the grooves are substantially impervious to damage. The teardrop shape of the projectile has several advantages over the round ball and conical type slug notably in the reduction of drag and improved ballistic coefficient. Further, the teardrop shape moves the center of mass of the projectile forward closer to the force of the spin generated by the turbo grooves, thereby substantially eliminating tumbling experienced with conical slugs. The spinning tear drop shape acts as a flying body, climbing in flight, which increases the range.
For use as a single slug-type projectile in a shell case, the teardrop-shaped slug is preferably centered in the case by use of a sabot with a cavity which conforms to the shape of the slug rearwardly of the grooves. The sabot aligns the axis of the slug with the center of the case and allows for a subcaliber slug producing greater velocity due to drag reduction.
In the multiple shot configuration, the projectiles fit together in a stack or stacks with the tail of the forward projetiles fitting into the recesses of the projectiles behind. This arrangement aligns the shot along a common axis and upon firing the projectiles separate after leaving the firearm barrel. As many as nine 0.30 caliber projectiles or twelve 0.28 caliber projectiles may be fired in this manner in three or four stacks of three projectiles per stack.
A single 12 gauge slug in accordance with the invention may weigh about 1 oz. and is 0.54 caliber. A 20 gauge slug is about 3/4 oz. and 0.45 caliber while a 0.30 caliber shot is 1/8 oz. in weight.
It is found in practice that four turbo grooves are sufficient to spin a projectile, the grooves being deep enough to engage the air in order to provide effective spin. When positioning projectiles in a shell, the recess in the center can be used to seat the projectile without deforming the grooves.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.